The problem with ODs is that they really are usually the most common and most abundant thing out there. Everyone and their uncle's uncle has a tubescreamer design, etc. Between Aion and Bugg there are a ton of "underrepresented" designs available too.
So, if you want to be unique, you may have to get weird with it. Or at least rare with it, so to speak.
Amp-in-a-box designs are always fun, though you may want to look at things other than the usual Vox/Marshall/Fender crowd. Sunn, Mesa, Dumble, aim for "Distinctive but under represented" (Granted this also could lead to "under selling")
Could also look at oddness or quirky. CMOS drivers, modulation, shove an envelope follower up its butt, something new and different. Gotta stand out some how, if you can. The Clari(not) has just about the simplest implementation of an envelope follower possible, and I've experimented with putting it all sorts of places it ought not be.... usually for good reason, its not exactly subtle.
Oh and yeah, we've reached an era where smd pads for JFETs is the way to go, unfortunately or not.